In magnetic heads and magnetic sensors, a magnetoresistive effect where the electrical resistance of a substance changes when a magnetic field is externally applied and the anomalous Hall effect where a voltage is applied in the direction perpendicular to the current are used. At present, magnetoresistive effects include a metal-based anisotropic magnetoresistive effect (AMR), a giant magnetoresistive effect (GMR) and a tunnel magnetoresistive effect (TMR).
In a GMR element, for example, the direction of the spin of the electrons that carry out a sense current flowing through the GMR element, that is to say, whether it is an up spin or a down spin, changes the difference in the direction in which a free layer is magnetized and in which a pinned layer is magnetized, and this difference in the status is used to store information.
In recent years, attention has been given to a so-called MRAM that forms a magnetic memory cell where the same element structure as those in the above-described magnetic heads and magnetic sensors is used to hold information due to the difference in the direction of magnetization of the magnetic body.
In these magnetic memory cells, information is read out using a magnetoresistive effect and information is written in by applying a magnetic field or by inverting the direction of magnetization through spin injection (see Patent Document 1 or Patent Document 2).
In the above-described magnetic heads, magnetic sensors and magnetic memories, a metal magnetic body is used as the magnetic body for holding magnetic information, and therefore information is read out or information is written into a magnetic memory cell by allowing a current to directly flow through the magnetic body.